1. Field of the Invention
Apparatus for ocular refraction with particular reference to means for facilitating over-refraction of aphakic patient.
2. Discussion of the Prior Art
Present day over-refraction of aphakic patients using spectacles frames of the brand, size and style intended to be worn requires the provision of kits of several permanently glazed frames of each brand and style. A particular kit representing a single brand and style of spectacles frame may include three or more glazed frames to cover a range of patient pupillary distances of from 60 mm to 68 mm in 2 mm to 4 mm increments.
In addition to the obvious high cost of such refracting equipment and limited selection of frame brand and style afforded the patient, repeated frame adjustment and readjustment for proper face fitting renders this refracting technique tedious, time consuming and difficult, not to mention the lack of accuracy of results attending the not infrequent need to use a glazed frame which does not precisely match the patient's PD.
A further drawback to the use of kits of frames in over-refraction is the short useful life of the frame due to obsolescence of style and/or material fatigue from repeated bending. Repair, storage and maintenance of frame cleanliness for multiple patient use is also problematic.
In view of the foregoing, it is an object of this invention to overcome the drawbacks of prior art over-refracting practices with simple, inexpensive and easily handled test lens means which is adaptable to a wide choice of spectacles frame brands, styles, and sizes.
More particularly, the invention has an objective of considerably minimizing the practioner's capital equipment cost by providing an essentially maintenance free lifetime test lens, i.e. a test lens having an adaptability to old, new and future spectacles frame styles.
A further object is to provide the aphakic with a wide choice of spectacles frames and fitting for over-refraction with the exact spectacles frame selected for ultimate wearing, i.e. to avoid the traditional separate frame fittings for refraction and wearing.
Other objects and advantages of the invention will become apparent from the following description.